Dipping into the well again....

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So there has been success from Freakers in finding  RGMAW LED's and other items I am looking for on this little project of mine, so I will see if the well has run dry yet.....

 

I am in search of a Pan/tilt mechanism that is motorised.  Not Servo driven.  And can run off of a battery.  The load it must pan/tilt shall weigh no more than 16 ounces/~500 grams. 

 

Ideally it will use stepper motors, but I am not too picky.  It would be great if it also had limit switches on it as well.

 

I ordered a unit off Aliexpress, and it arrived today, but is very disappointing to put it politely

 

JIm.

 

 

I would rather attempt something great and fail, than attempt nothing and succeed - Fortune Cookie

 

"The critical shortage here is not stuff, but time." - Johan Ekdahl

 

"Step N is required before you can do step N+1!" - ka7ehk

 

"If you want a career with a known path - become an undertaker. Dead people don't sue!" - Kartman

"Why is there a "Highway to Hell" and only a "Stairway to Heaven"? A prediction of the expected traffic load?"  - Lee "theusch"

 

Speak sweetly. It makes your words easier to digest when at a later date you have to eat them ;-)  - Source Unknown

Please Read: Code-of-Conduct

Atmel Studio6.2/AS7, DipTrace, Quartus, MPLAB, RSLogix user

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Are you looking for a $25 item, $70 item, $200 item (ex: difference between metal and plastic components)   Do you need a position feedback for each axis (beyond limit switches)?  is slow creepy adjustment ok, or does it need to move fast (like following a joystick in "real  time")?

 

This looked kinda neat---but maybe it is 100% garbage??? I don't know if it is servo, stepper, or nuclear

 

https://www.ebay.com/itm/1750495...

When in the dark remember-the future looks brighter than ever.   I look forward to being able to predict the future!

Last Edited: Wed. Apr 13, 2022 - 04:51 AM
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I saw a similar mount and it certainly fits the specs, but I forgot to mention that the mount needs to sit flat on a table, or on the ground.

 

Thanks for teh lead though.

 

JIm

I would rather attempt something great and fail, than attempt nothing and succeed - Fortune Cookie

 

"The critical shortage here is not stuff, but time." - Johan Ekdahl

 

"Step N is required before you can do step N+1!" - ka7ehk

 

"If you want a career with a known path - become an undertaker. Dead people don't sue!" - Kartman

"Why is there a "Highway to Hell" and only a "Stairway to Heaven"? A prediction of the expected traffic load?"  - Lee "theusch"

 

Speak sweetly. It makes your words easier to digest when at a later date you have to eat them ;-)  - Source Unknown

Please Read: Code-of-Conduct

Atmel Studio6.2/AS7, DipTrace, Quartus, MPLAB, RSLogix user

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You could mod with a bandsaw, at least it would sit flat....maybe these folks make 10 variations...finding ou t who is the fun part

 

 

When in the dark remember-the future looks brighter than ever.   I look forward to being able to predict the future!

Last Edited: Wed. Apr 13, 2022 - 03:25 PM
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Yup.

This is a bit of a niche project.  Not too sure how its all going to pan out (no pun intended).  I also may need 10 of these so a bandsaw mod wont look so neat.

 

The search continues

 

JIm

I would rather attempt something great and fail, than attempt nothing and succeed - Fortune Cookie

 

"The critical shortage here is not stuff, but time." - Johan Ekdahl

 

"Step N is required before you can do step N+1!" - ka7ehk

 

"If you want a career with a known path - become an undertaker. Dead people don't sue!" - Kartman

"Why is there a "Highway to Hell" and only a "Stairway to Heaven"? A prediction of the expected traffic load?"  - Lee "theusch"

 

Speak sweetly. It makes your words easier to digest when at a later date you have to eat them ;-)  - Source Unknown

Please Read: Code-of-Conduct

Atmel Studio6.2/AS7, DipTrace, Quartus, MPLAB, RSLogix user

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Have you looked at the T/P mounts used on drones?

Would that work for you? something like this:  https://www.adafruit.com/product...

 

FF = PI > S.E.T

 

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ki0bk wrote:

Have you looked at the T/P mounts used on drones?

Would that work for you? something like this:  https://www.adafruit.com/product...

 

YEs, and they are not strong enough to tilt a 16oz/500G object attached to them.  They also use power to stay in position so battery pack life suffers.  Hence usiing a motorised mount.

 

Right side Jim

I would rather attempt something great and fail, than attempt nothing and succeed - Fortune Cookie

 

"The critical shortage here is not stuff, but time." - Johan Ekdahl

 

"Step N is required before you can do step N+1!" - ka7ehk

 

"If you want a career with a known path - become an undertaker. Dead people don't sue!" - Kartman

"Why is there a "Highway to Hell" and only a "Stairway to Heaven"? A prediction of the expected traffic load?"  - Lee "theusch"

 

Speak sweetly. It makes your words easier to digest when at a later date you have to eat them ;-)  - Source Unknown

Please Read: Code-of-Conduct

Atmel Studio6.2/AS7, DipTrace, Quartus, MPLAB, RSLogix user

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jgmdesign wrote:
They also use power to stay in position so battery pack life suffers. 

Thanks for the clarification of the spec's Jim!

 

FF = PI > S.E.T

 

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So you don't want RC servo drive (Technically, PWM-driven potentiometer feedback gear motors), but you're okay with steppers.

 

The weight of your load is mostly irrelevant, what's important is the torque you think it should maintain without power applied.  That will definitely imply a gear motor - steppers will backdrive given a bit of torque on them, so you will need to put power into them to keep them still (rather more than RC servo drive, I'd think!).  I could be wrong - feel free to correct.

 

The best anti-backdrives are going to be worm gears.  This outfit has some:

 

http://www.eaglepantilt.com/

 

Never mind.  They updated their website, and are apparently out of that business.

S.

 

PS - If it helps, I know an outfit that does make highly geared pan-tilt assemblies, but they're not really generally into selling them separately.  They have about 100:1 geartrains, and are servos, but not in the 'RC' servo sense - they have optical encoders on them and are dependent upon proper driving and feedback control electronics.  You could probably use a couple of $250 'geckodrives' to run them, but the mechanical assembly would probably run well into four figures.  At a certain point, it becomes cheaper to make your own.  S.

Last Edited: Wed. Apr 13, 2022 - 07:52 PM
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Maybe just screw the arm down on a chunk of extrusion or steel plate.  

Most of these lightweights will need some sort of base to stay put, or they'll blow over when you sneeze and change direction if jostled.

When in the dark remember-the future looks brighter than ever.   I look forward to being able to predict the future!

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Scroungre wrote:
So you don't want RC servo drive (Technically, PWM-driven potentiometer feedback gear motors), but you're okay with steppers.

NOt sure if this is a question, or a confrontation, but I am going to go with the former...Yes, Steppers is the way I would like to go, but I am open to other ideas.

 

Scroungre wrote:
That will definitely imply a gear motor - steppers will backdrive given a bit of torque on them, so you will need to put power into them to keep them still (rather more than RC servo drive, I'd think!).  I could be wrong - feel free to correct.

If you short the coils of a stepper motor the motor will not turn...easily.  The ones I have here wont even turn when I anchor their mounting flanges in a vise and try turning the shaft with a pair of pliers.  So in theory I could energise a low power relay when I want to connect the stepper driver to the coils and spin the motor, then de-energise the circuit/relays and the motor will hold its position.

 

Scroungre wrote:
The best anti-backdrives are going to be worm gears.

Yes, and the smoothest movement too.

 

Scroungre wrote:
PS - If it helps, I know an outfit that does make highly geared pan-tilt assemblies, but they're not really generally into selling them separately.  They have about 100:1 geartrains, and are servos, but not in the 'RC' servo sense - they have optical encoders on them and are dependent upon proper driving and feedback control electronics.  You could probably use a couple of $250 'geckodrives' to run them, but the mechanical assembly would probably run well into four figures.  At a certain point, it becomes cheaper to make your own.  S.

Thank you for the offer/idea.  We are thinking of using the crappy P/T mount we bought from AliExpress and have my metal shop make a 'beefier' unit from my shop drawings.  I have to dissect the crappy one first though.

 

Jim

I would rather attempt something great and fail, than attempt nothing and succeed - Fortune Cookie

 

"The critical shortage here is not stuff, but time." - Johan Ekdahl

 

"Step N is required before you can do step N+1!" - ka7ehk

 

"If you want a career with a known path - become an undertaker. Dead people don't sue!" - Kartman

"Why is there a "Highway to Hell" and only a "Stairway to Heaven"? A prediction of the expected traffic load?"  - Lee "theusch"

 

Speak sweetly. It makes your words easier to digest when at a later date you have to eat them ;-)  - Source Unknown

Please Read: Code-of-Conduct

Atmel Studio6.2/AS7, DipTrace, Quartus, MPLAB, RSLogix user

Last Edited: Thu. Apr 14, 2022 - 01:49 AM